Classifications

• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
  • C10M3/00—Liquid compositions essentially based on lubricating components other than mineral lubricating oils or fatty oils and their use as lubricants; Use as lubricants of single liquid substances
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
  • F16D69/00—Friction linings; Attachment thereof; Selection of coacting friction substances or surfaces
  • F16D69/02—Compositions of linings; Methods of manufacturing
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
  • C01G19/00—Compounds of tin
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
  • C10M103/00—Lubricating compositions characterised by the base-material being an inorganic material
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
  • C10M103/00—Lubricating compositions characterised by the base-material being an inorganic material
  • C10M103/06—Metal compounds
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
  • F16D2200/00—Materials; Production methods therefor
  • F16D2200/006—Materials; Production methods therefor containing fibres or particles
  • F16D2200/0073—Materials; Production methods therefor containing fibres or particles having lubricating properties

Definitions

• the present invention relates to solid lubricants and solid lubricant combinations based on tin sulfide and carbon, a process for their preparation and their
• solid lubricants for friction linings based on graphites, sulfides and combinations of these compounds with fluorides and phosphates have also been known for a long time.
• a known and widely used solid lubricant is e.g. B. lead sulfide. Due to the increasing ecological awareness of heavy metals and the associated efforts to reduce their use, lead sulfide is also only available to an increasingly limited extent.
• Another representative from the group of metal sulfides, which has a widespread use in friction linings found is antimony sulfide.
• the present invention is therefore based on the object of providing a solid lubricant and a solid lubricant combination which have comparable or even better tribological properties than the solid lubricants known from the prior art and combinations derived therefrom, but are free from compounds which are ecologically or toxicologically questionable.
• Such solid lubricants are produced by reacting metallic tin in finely divided form with sulfur and carbon under an inert gas or air atmosphere at temperatures from 200 ° to 1500 ° C., preferably 800-1200 ° C., for 0.1 to 6 hours, preferably 40 to 80 minutes, with sulfur in an at least stoichiometric amount, calculated on the sole formation of SnS 2 , and carbon are available in an amount of 0.5 to 20 wt .-%, based on the total weight of the reaction batch, are used in the reaction batch.
• the carbon obviously has an action comparable to the action of ammonium chloride or other known acid catalysts, which is documented by the formation of large amounts of SnS 2 in the solid lubricant obtainable in this way.
• the carbon remains in the tin sulfide matrix formed as a reaction product and, according to the investigations of the inventors, is statistically distributed in this.
• the tin sulfides forming the tin sulfide matrix can be calculated purely as an externally uncharged compound of the formula
• Solid lubricant approx. 50-90% by weight of tin (IV) sulfide and 10-50% by weight of other tin sulfide, in particular Zn (II) sulfide on the total amount of tin sulfides contained therein.
• the carbon content is approximately 0.5-20% by weight based on the total weight of the solid lubricant.
• Solid lubricant is first mixed with finely divided metallic tin with sulfur and carbon.
• the sulfur is used in an at least stoichiometric amount, which is calculated for the complete conversion of the tin to SnS. A small stochiometric excess of sulfur of up to 5%, calculated on the formation of SnS 2 , is preferably used.
• the carbon is used in an amount of 0.5 to 20% by weight, based on the total weight of the reaction mixture. After mixing, the reaction mixture is reacted under an inert gas or air atmosphere at temperatures from 200 ° to 1500 ° C. for 0.1 to 6 hours. After the end of the reaction, the product obtained in this way is allowed to cool, which is then ground.
• the carbon is used in an amount of 2-8% by weight and in particular in an amount of 5% by weight, based on the weight of the finished reaction mixture, in the process according to the invention.
• the carbon is used in the form of graphite in the reaction mixture.
• the graphite can be of natural as well as synthetic origin. However, it is also possible to use other modifications of the carbon such as e.g. B. to use carbon black.
• the tin sulfide reaction product obtainable by the process according to the invention can be used both as a solid lubricant in general and specifically as an additive of friction lining mixtures.
• the tin sulfide and graphite solid lubricant containing in an amount of 0.5% to 15 wt .-%, preferably used in an amount of 5 wt .-%.
• These friction lining mixtures obtainable in this way are primarily used in friction linings, preferably in resin-bonded friction linings and in particular in friction linings such as clutch or brake linings.
• the positive influence on the wear behavior of such friction linings achieved by the solid lubricant according to the invention is comparable or even better with the relevant effect of antimony (III) oxide. Go further with the good achieved
• Solid lubricant can, however, not only be used as the sole additive to friction lining mixtures, but is also used according to a further development of the present invention for producing a solid lubricant combination. Those made using this solid lubricant combination
• Friction linings also have at least the same wear behavior as the friction linings, which are produced with the aid of solid lubricant combinations containing antimony sulfide.
• the solid lubricant combination of the present invention is produced by 2 to 50% by weight of the above-described tin sulfide-based solid lubricant with 2 to 40% by weight graphite, 2 to 40% by weight zinc sulfide, 2 to 30% by weight tin (II) sulfide, 1 to 5% by weight of free sulfur and 2 to 40% by weight of an alkaline earth metal phosphate or a metal phosphate in an intensive mixer, for example in a tumble mixer, in each case in finely divided form and the components are subsequently mixed therein.
• the solid lubricant combination is still ground in order to obtain a relatively uniform particle size.
• the particle size should be in the range after grinding of approx. 5 to 45 ⁇ m in order to ensure sufficient miscibility when used as an additive in the mixing process with the other components.
• alkaline earth metal phosphates and metal phosphates that can be used as solid lubricants can be used to produce the solid lubricant combination.
• Calcium phosphate, magnesium phosphate, aluminum phosphate, iron phosphate or zinc pyrophosphate is preferably used. Mixtures of at least two of these metal or alkaline earth metal phosphates can also be used.
• this solid lubricant combination which is available in this way, is also used in the production of friction lining mixtures. It is used in an amount of 0.5 to 15.0% by weight, based on the total weight of the friction lining mixture.
• These mixtures in turn can in turn be processed into friction linings, in particular friction linings such as clutch or brake linings.
• Example 1 Production Example 119 g of tin powder were mixed with 71 g of sulfur, corresponding to a stoichiometric excess of 10%, based on the formation of SnS 2 , and with about 9 g of graphite (corresponding to 5% by weight of the finished reaction mixture). The reaction mixture was then reacted in a conventional muffle furnace at 200-800 ° C under a protective gas atmosphere for 6 hours. After cooling, the reaction product was ground and examined for its chemical composition.
• the proportion of tin (IV) sulfide in the tin sulfide matrix formed was approximately 70% by weight and the remaining 30% by weight of the sulfidic portion predominantly as Zn (II) sulfide.
• Disc brake pad formulations used (Tab. 1). The recipes without solid lubricant, which were also examined as a reference in the test series, were first mixed in a ploughshare mixer with a cutter head. Then these were then pressed in a pressure and temperature-controlled laboratory press into standard vehicle brake pads. To produce the test specimens containing solid lubricant, the solid lubricants to be compared were divided into the respective proportions in equal proportions between these two steps
• test coverings produced in this way were then tested on a Krauss test bench.
• Table 1 Composition of the brake lining test formulations containing solid lubricant
• test program particular attention was paid to the wear properties at high loads, since the favorable properties of the carbon-containing tin sulfide are particularly evident under these conditions.
• the test program included in detail
• the weight loss in grams per covering was determined.
• the wear values given in Tables 2 and 3 are based on the weight loss at 100 ° C of the corresponding reference surface (surface 0), which had the same composition apart from the missing solid lubricant.

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• 1998
  • 1998-04-09 DE DE19815992A patent/DE19815992C2/de not_active Expired - Lifetime
• 1999
  • 1999-04-09 DE DE59904628T patent/DE59904628D1/de not_active Expired - Lifetime
  • 1999-04-09 PL PL99343175A patent/PL343175A1/xx unknown
  • 1999-04-09 KR KR10-2000-7011071A patent/KR100400682B1/ko not_active IP Right Cessation
  • 1999-04-09 AT AT99920629T patent/ATE234907T1/de active
  • 1999-04-09 ES ES99920629T patent/ES2192846T3/es not_active Expired - Lifetime
  • 1999-04-09 EP EP99920629A patent/EP1070109B1/de not_active Expired - Lifetime
  • 1999-04-09 JP JP2000543546A patent/JP3605565B2/ja not_active Expired - Lifetime
  • 1999-04-09 WO PCT/EP1999/002426 patent/WO1999052997A1/de active IP Right Grant
• 2000
  • 2000-10-06 US US09/673,004 patent/US6303545B1/en not_active Expired - Lifetime

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